As a conventional example, a lighting device is introduced in a document 1 [JP 2015-002157 A]. The lighting device (a horizontal light) of the document 1 is installed to illuminate a wall surface (a horizontal surface) as a background in such as TV studios and stages. Examples of the horizontal light include a lower horizontal light which is installed at a floor side, and an upper horizontal light which is installed at a ceiling side. The horizontal light includes a lighting source unit, a power source unit to supply power to the lighting source unit, and a supporting unit to support the lighting source unit from the power source unit. The lighting source unit is placed with an incline posture which a predetermined angle faces upwards so that a front surface emitting the light faces toward a diagonally upward against a wall surface.
The lighting source unit includes a main body that is contained by a cover and a case which has an opening opened at a front surface. A light-emitting unit including a substrate on which plural LEDs are mounted and a reflection means are contained within the case. The plural LEDs are placed to form LED lines as lines along a horizontal direction on the substrate, and the LED lines are arranged to a top-and-bottom direction on the substrate. The reflection means includes a pair of reflection panels in the top-and-bottom direction which reflects light emitted to the top-and-bottom direction from the plural LEDs toward the opening.
Incidentally, the lighting device (horizontal light) of the document 1 is installed at either a lower place (floor side) or an upper place (ceiling side) relative to the wall surface (illuminated surface of a target). The lighting device controls a light distribution using a pair of reflection panels placed to the top-and-bottom direction of each of LED lines so that the lighting device emits light upward from the floor when being installed at the floor side and the lighting device emits light downward from the ceiling side when being installed at the ceiling surface.
However, the reflection panels of a constitution shown in the document 1 may occur an irregular illumination of the illuminated surface of the target.